This invention relates generally to the control of power in an electronic integrated circuit such as a data acquisition system (DAS), and more particularly the invention is directed to control of power without the need for a dedicated circuit pin.
A data acquisition system such as the Linear Technology Corporation LTC1290 single chip data acquisition system contains a serial I/O successive approximation A/D converter. The device uses switch capacitor technology to perform either 12 bit unipolar or 11 bit plus sign bipolar A/D conversions. An 8 channel input multiplexer can be configured for either single ended or differential inputs, or combinations thereof. An on-chip sample and hold is included for all single ended input channels. When the circuit is idle, it can be powered down in applications where low power consumption is desired.
The circuit is packaged in a 20 lead ceramic DIP. Heretofore, control of power shutdown in such electronic circuits have required a dedicated package pin. Alternatively, external control has been used by actually disconnecting the power source from the circuit.
The present invention is directed to controlling and implementing a power shutdown from within the circuit but without the need for a dedicated pin.